* {
  margin: 0;
  padding: 0;
  list-style: none;
  -webkit-box-sizing: border-box;
          box-sizing: border-box;
}

html,
body {
  height: 100%;
}

@-webkit-keyframes tip {
  0% {
    opacity: 0;
  }
  20% {
    opacity: 1;
  }
  80% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}

@keyframes tip {
  0% {
    opacity: 0;
  }
  20% {
    opacity: 1;
  }
  80% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}

.web {
  font-size: 26px;
  width: 100%;
  height: 100%;
}

.web > div {
  width: 100%;
  height: 100%;
  position: fixed;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-pack: center;
      -ms-flex-pack: center;
          justify-content: center;
  -ms-flex-line-pack: center;
      align-content: center;
  -ms-flex-wrap: wrap;
      flex-wrap: wrap;
  left: 0;
  top: 0;
  text-align: center;
}

.web .first-page {
  background-color: skyblue;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -ms-flex-wrap: wrap;
      flex-wrap: wrap;
  -webkit-box-pack: center;
      -ms-flex-pack: center;
          justify-content: center;
  -ms-flex-line-pack: center;
      align-content: center;
}

.web .first-page > div {
  width: 100%;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -ms-flex-wrap: wrap;
      flex-wrap: wrap;
  -webkit-box-pack: center;
      -ms-flex-pack: center;
          justify-content: center;
  -ms-flex-line-pack: center;
      align-content: center;
}

.web .first-page ~ div {
  display: none;
  -webkit-box-pack: center;
      -ms-flex-pack: center;
          justify-content: center;
}

.web .second-page {
  background-color: pink;
}

.web .second-page .list {
  width: 80%;
  -webkit-box-shadow: 0 0 20px white;
          box-shadow: 0 0 20px white;
  max-height: 400px;
  overflow: auto;
  padding: 0 40px;
}

.web .second-page .list li {
  margin: 20px 0;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-pack: justify;
      -ms-flex-pack: justify;
          justify-content: space-between;
}

.web .second-page .tip {
  width: 200px;
  height: 90px;
  line-height: 90px;
  background-color: antiquewhite;
  position: fixed;
  top: 50%;
  left: 50%;
  -webkit-transform: translate(-50%, -50%);
          transform: translate(-50%, -50%);
  display: none;
}

.web .second-page .tip-active {
  display: block;
  -webkit-animation: tip 2s forwards;
          animation: tip 2s forwards;
}
